Chronic inflammatory diseases are associated with accelerated atherosclerosis and increased risk of cardiovascular diseases (CVD). As the pathogenesis of atherosclerosis is increasingly recognized as ...an inflammatory process, similarities between atherosclerosis and systemic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel diseases, lupus, psoriasis, spondyloarthritis and others have become a topic of interest. Endothelial dysfunction represents a key step in the initiation and maintenance of atherosclerosis and may serve as a marker for future risk of cardiovascular events. Patients with chronic inflammatory diseases manifest endothelial dysfunction, often early in the course of the disease. Therefore, mechanisms linking systemic inflammatory diseases and atherosclerosis may be best understood at the level of the endothelium. Multiple factors, including circulating inflammatory cytokines, TNF-α (tumor necrosis factor-α), reactive oxygen species, oxidized LDL (low density lipoprotein), autoantibodies and traditional risk factors directly and indirectly activate endothelial cells, leading to impaired vascular relaxation, increased leukocyte adhesion, increased endothelial permeability and generation of a pro-thrombotic state. Pharmacologic agents directed against TNF-α-mediated inflammation may decrease the risk of endothelial dysfunction and cardiovascular disease in these patients. Understanding the precise mechanisms driving endothelial dysfunction in patients with systemic inflammatory diseases may help elucidate the pathogenesis of atherosclerosis in the general population.
Oxidative stress in cardiovascular disease Csányi, Gábor; Miller, Jr, Francis J
International journal of molecular sciences,
04/2014, Letnik:
15, Številka:
4
Journal Article
Recenzirano
Odprti dostop
In the special issue "Oxidative Stress in Cardiovascular Disease" authors were invited to submit papers that investigate key questions in the field of cardiovascular free radical biology. The ...original research articles included in this issue provide important information regarding novel aspects of reactive oxygen species (ROS)-mediated signaling, which have important implications in physiological and pathophysiological cardiovascular processes. The issue also included a number of review articles that highlight areas of intense research in the fields of free radical biology and cardiovascular medicine.
An unprespecified interim analysis of results from a phase 1–2 study of gene therapy for sickle cell disease shows resolution of severe vaso-occlusive events in 25 patients who could be evaluated. In ...the 24 months before enrollment, these patients had a median of 3.5 severe vaso-occlusive events per year.
The epidermal growth factor receptor (EGFR) family and its ligands serve as a switchboard for the regulation of multiple cellular processes. While it is clear that EGFR activity is essential for ...normal cardiac development, its function in the vasculature and its role in cardiovascular disease are only beginning to be elucidated. In the blood vessel, endothelial cells and smooth muscle cells are both a source and a target of EGF-like ligands. Activation of EGFR has been implicated in blood pressure regulation, endothelial dysfunction, neointimal hyperplasia, atherogenesis, and cardiac remodeling. Furthermore, increased circulating EGF-like ligands may mediate accelerated vascular disease associated with chronic inflammation. Although EGFR inhibitors are currently being used clinically for the treatment of cancer, additional studies are necessary to determine whether abrogation of EGFR signaling is a potential strategy for the treatment of cardiovascular disease.
Since its discovery in 1999, a number of studies have evaluated the role of Nox1 NADPH oxidase in the cardiovascular system. Nox1 is activated in vascular cells in response to several different ...agonists, with its activity regulated at the transcriptional level as well as by NADPH oxidase complex formation, protein stabilization and post-translational modification. Nox1 has been shown to decrease the bioavailability of nitric oxide, transactivate the epidermal growth factor receptor, induce pro-inflammatory signalling, and promote cell migration and proliferation. Enhanced expression and activity of Nox1 under pathologic conditions results in excessive production of reactive oxygen species and dysregulated cellular function. Indeed, studies using genetic models of Nox1 deficiency or overexpression have revealed roles for Nox1 in the pathogenesis of cardiovascular diseases ranging from atherosclerosis to hypertension, restenosis and ischaemia/reperfusion injury. These data suggest that Nox1 is a potential therapeutic target for vascular disease, and drug development efforts are ongoing to identify a specific bioavailable inhibitor of Nox1.
The incidence of thrombotic events increases during aging, but the mechanisms are not well understood. To investigate the prothrombotic role of oxidative stress during aging, we tested the hypothesis ...that aged mice overexpressing the antioxidant enzyme glutathione peroxidase-1 (Gpx1) are protected from experimental thrombosis.
Susceptibility to carotid artery thrombosis was first examined in wild-type C57BL/6J mice. After photochemical injury of the carotid artery, the time to stable occlusion was significantly shorter in 12- and 18-month-old mice compared with 4-month-old mice (P<0.01). Unlike wild-type mice, transgenic mice overexpressing Gpx1 (Gpx1 Tg) did not exhibit shortened times to occlusion of the carotid artery at 12 or 18 months of age. Wild-type mice also exhibited increased susceptibility to venous thrombosis after inferior vena cava ligation at 12 or 18 months of age (P<0.05 versus 4 months of age). Gpx1 Tg mice were protected from this aging-related enhanced susceptibility to venous thrombosis. Age-dependent platelet hyperactivation, evidenced by increased hydrogen peroxide, fibrinogen binding, and activation of fibrinogen receptor αIIbβ3, was observed in thrombin-activated platelets from wild-type but not Gpx1 Tg mice (P<0.05). Enhanced platelet activation responses in aged mice were also prevented by polyethylene glycol-catalase or apocynin, an inhibitor of NADPH oxidase. Aged mice displayed increased intraplatelet expression of p47(phox) and superoxide dismutase-1, suggesting a mechanistic pathway for increased hydrogen peroxide generation.
Our findings demonstrate that hydrogen peroxide is a key mediator of platelet hyperactivity and enhanced thrombotic susceptibility in aged mice.
Abstract Objective Examine the contribution of Nox1 NADPH oxidase to atherogenesis. Methods and results Male apolipoprotein E deficient mice (ApoE−/− ) and male mice deficient in both apolipoprotein ...E and Nox1 (ApoE−/− Nox1−/y ) received an atherogenic diet for 18 weeks. Mean blood pressures, body weights, and serum cholesterol levels were similar between the two groups of mice. Deficiency of Nox1 decreased superoxide levels and reduced lesion area in the aortic arch from 43% (ApoE−/− ) to 28% (ApoE−/− Nox1−/y ). The reduction in lesion size at the level of the aortic valve in ApoE−/− /Nox1−/y was accompanied by a decrease in macrophage infiltration as compared to ApoE−/− mice. Carotid artery ligation in ApoE−/− mice induced accelerated intimal hyperplasia with decreased cellular proliferation and increased collagen content in the neointima of vessels deficient in Nox1. Conclusions Nox1-derived ROS modify lesion composition and contribute to lesion size in a murine model of atherosclerosis.
Recent reports demonstrate that multiple forms of cardiovascular stress, including pressure overload, chronic ischemia, and infarction-reperfusion injury, provoke an increase in autophagic activity ...in cardiomyocytes. However, nothing is known regarding molecular events that stimulate autophagic activity in stressed myocardium. Because autophagy is a highly conserved process through which damaged proteins and organelles can be degraded, we hypothesized that stress-induced protein aggregation is a proximal trigger of cardiomyocyte autophagy.
Here, we report that pressure overload promotes accumulation of ubiquitinated protein aggregates in the left ventricle, development of aggresome-like structures, and a corresponding induction of autophagy. To test for causal links, we induced protein accumulation in cultured cardiomyocytes by inhibiting proteasome activity, finding that aggregation of polyubiquitinated proteins was sufficient to induce cardiomyocyte autophagy. Furthermore, attenuation of autophagic activity dramatically enhanced both aggresome size and abundance, consistent with a role for autophagic activity in protein aggregate clearance.
We conclude that protein aggregation is a proximal trigger of cardiomyocyte autophagy and that autophagic activity functions to attenuate aggregate/aggresome formation in heart. Findings reported here are the first to demonstrate that protein aggregation occurs in response to hemodynamic stress, situating pressure-overload heart disease in the category of proteinopathies.
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